1. Field of the Invention
The present invention relates to the field of packaging and preservation of foods and more particularly to a composition and method for preserving foodstuffs with a fat based edible coating.
2. Description of the Prior Art
The living patterns of modern society have resulted in large populations of people located at considerable distances from the sites of agriculture and the sources of food. These people nonetheless desire fresh meats and fruits and vegetables. In addition to the time required for transportation of fresh foods to these populations, there is also a time requirement for storage of fresh foods at the point of distribution before the food is used by the ultimate consumer. Most fruits and vegetables begin to deteriorate and lose some of their nutritional value, as well as their characteristics of freshness, as soon as they are harvested. The length of possible storage time varies with the type of fruit or vegetable and for example, it may extend from 3 to 12 weeks under conventional storage conditions for oranges. (for example) Freshly slaughtered meat may be stored under refrigeration without any protective treatment for approximately one to two weeks. Then it deteriorates rapidly with the development of an undesirable odor, color changes, and tissue breakdown, and ultimately becomes unsuitable for human consumption.
Various processes have been developed for extending the shelf life or storage time of some foods, such as curing, dehydration, canning and freezing. These processes subject the food to certain irreversible reactions in many cases, however, which destroy the fresh quality of the foods.
The shelf lives of some fruits and vegetables have been extended by the application of certain resins, shellacs, vegetable wax or paraffin to their outer surface. But after an extended time, even these coated fruits and vegetables lose their retained moisture and freshness. In addition, many consumers object to preservative coatings or sprays which are not easily removed and are consumed with the food.
In the wholesale meat industry and in particular, that part of the industry which supplies portion-controlled servings of meat to the food service industry, the current storage method for meat is to enclose it in a plastic wrap either by means of a vacuum and heat-sealing process known as BIVAC or by means of a perimeter heat-sealed bag known as CRYOVAC. These sealing methods may increase the refrigerated shelf life of meat to a maximum of 30 days from slaughter but they allow the meat to lose a certain percentage of its weight in nonrecoverable meat juices which is called drip loss.
If the meat is frozen it may be stored for several months or longer. However freezing may also cause certain changes in the water-holding capacity of the meat and unless the freezing and thawing process is done very carefully there may be a denaturation of meat protein, freezer burn, or a large drip loss upon thawing. Because of these possible structural changes due to freezing, it is preferable for the best grades of meats to be shipped chilled rather than frozen.
In addition, there is an increased energy cost in maintaining meat in a frozen state rather than in keeping it chilled. Transportation costs are also greater for shipping frozen meat because of the need to use very low temperature compartments for the meat or to ship it by air freight. It would be much less difficult and accordingly, more economical to transport chilled meat and other foods to more distant points of demand by surface methods.
Many members of the population are also concerned about possible adverse health effects which may result from the use of plastic coverings or synthetic coatings which contact the food directly and may interact with it. In addition, government agencies regulating coating ingredients and processes for use with food have proven to be more willing to approve products, additives and processes derived from or utilizing natural ingredients or sources than those having synthetic origins.
There is thus a need for a preservative coating and a method for preserving foods which extends the presently limited storage time for foods, including fruits and vegetables and especially meats, without substantially affecting their quality. There is also a need for a method and a preservative coating which utilizes relatively inexpensive, naturally-occurring ingredients. The method and composition of the present invention overcome these problems, and surprisingly, at least double the expected shelf life of meats and other foods that have been so coated, thereby extending the potential shipment time of food products and enabling members of the wholesale food industry to utilize less expensive methods of shipping. The method and composition of this invention also substantially reduce drip loss of meat and moisture loss in other foods and allow the foods to retain their fresh characteristics for a longer period of time than by conventional methods.